It seems as though you may be experiencing symptoms of depression. You have negative thoughts, you don’t feel good about yourself and you are withdrawing from friends and family. Your feelings may be related to the breakup of your parents’ marriage or their contentious relationship. They may be so focused on battling each other that they are neglecting your emotional needs.
Another aspect of this problem is that you have been without your mother for four years. It is unclear why you have not seen your mother for such a long time but this likely is contributing to your problems.
I would strongly advise you to speak to your father or other members of your family about the possibility of professional help. Don’t ignore these problems. Your symptoms need to be addressed. It seems as though your father is currently unable to meet your emotional needs and if that is the case, then you should seek help from a mental health professional. A therapist can assist you in developing coping skills and the processing of your feelings in a psychologically healthy way.
If you feel uncomfortable approaching your father about this issue, then as soon as school begins next month, speak to a guidance counselor. The guidance counselor could assist you in addressing these problems or refer you to a mental health professional.
In the meantime, force yourself to be in the presence of others. That may not be easy but do it anyway. The less that you are isolated, the better. Isolation increases the likelihood of negative feelings. I would also encourage you to begin writing in a journal. A journal could be helpful in a number of ways including being a release for your emotions and documenting your symptoms. When and if you have the opportunity to meet with a mental health professional, having those notes from your journal could greatly assist the therapist in determining what might be wrong. Please take care.